The Solution To The Bubble Fefect Problem In0.13μm Copper Interconnection Process

According to Moore law, the circuit numbers in IC will double every18months, so more the circuit numbers are, smaller the scale of semiconductor device will be. When the critical size becomes smaller, the request to the IC manufacture will be higher. Thus the copper line instead of aluminum line is the inevitable result, and using low K dielectric material, the delay that caused by the metal line have been reduced to an acceptable level. Damascus process solved the problem of copper etching, and the scale of semiconductor device become smaller and smaller.This article analyzes the root cause to solve the bubble defect in0.13μm copper interconnection technology. And we find the theory for the occurrence of the bubble defect by inline defect scan, SEM cut, and verify the feasibility and reliability through the experiment data collection and analysis.SIN film works as the etch stop layer in Cu interconnect Damascus technology, high stress combined with the thermal and etch effects in the process, induced SIN peeling from the IMD film and forming the bubble defect. This article describes three solutions:modify and control IMD layer etch rate, change BARC deposition method from one step to two step, and add one design rule check for new product tape out, these three methods can avoid the occurrence of bubble defect, thus reduce the wafer scrap rate and improve the product yield.